package com.lagou.edu.factory;

import com.lagou.edu.annotation.Autowired;
import com.lagou.edu.annotation.Service;
import com.lagou.edu.annotation.Transactional;
import com.lagou.edu.pojo.Account;
import com.lagou.edu.utils.TransactionManager;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

import java.lang.annotation.Annotation;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

import org.springframework.core.annotation.AnnotationUtils;

/**
 * @author 应癫
 *
 *
 * 代理对象工厂：生成代理对象的
 */
@Service("proxyFactory")
public class ProxyFactory {

    @Autowired
    private TransactionManager transactionManager;

    public void setTransactionManager(TransactionManager transactionManager) {
        this.transactionManager = transactionManager;
    }


    /**
     * Jdk动态代理
     * @param obj  委托对象
     * @return   代理对象
     */
    public Object getJdkProxy(Object obj) {

        // 获取代理对象
        return  Proxy.newProxyInstance(obj.getClass().getClassLoader(), obj.getClass().getInterfaces(),
                new InvocationHandler() {
                    @Override
                    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                        Object result = null;
                        
                        // 类上，方法上 是否有 事务注解
                        boolean hasTransaction =false;
                        Class<? extends Object> class1 = obj.getClass();
                        if (class1.isAnnotationPresent(Transactional.class)) {
                        	hasTransaction= true;
						}
                        if (!hasTransaction) {
							Method[] methods = class1.getDeclaredMethods();
							for (Method method1 : methods) {
								if (method1.getName().equals(method.getName())) {
									Transactional annotation = method1.getAnnotation(Transactional.class);
									if (null != annotation) {
										hasTransaction = true;
									}
									break;
								}
							} 
						}
                        try{
                            if (hasTransaction) {
								// 开启事务(关闭事务的自动提交)
								transactionManager.beginTransaction();
							}
							result = method.invoke(obj,args);

                            // 提交事务

                            if (hasTransaction) {
								transactionManager.commit();
							}
                        }catch (Exception e) {
                            e.printStackTrace();
                            if (hasTransaction) {
								// 回滚事务
								transactionManager.rollback();
							}
							// 抛出异常便于上层servlet捕获
                            InvocationTargetException target = (InvocationTargetException) e;
                            Throwable targetException = target.getTargetException();
                            throw targetException;

                        }

                        return result;
                    }
                });

    }


    /**
     * 使用cglib动态代理生成代理对象
     * @param obj 委托对象
     * @return
     */
    public Object getCglibProxy(Object obj) {
        return  Enhancer.create(obj.getClass(), new MethodInterceptor() {
            @Override
            public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
                Object result = null;
                try{
                    // 开启事务(关闭事务的自动提交)
                    transactionManager.beginTransaction();

                    result = method.invoke(obj,objects);

                    // 提交事务

                    transactionManager.commit();
                }catch (Exception e) {
                    e.printStackTrace();
                    // 回滚事务
                    transactionManager.rollback();

                    // 抛出异常便于上层servlet捕获
                    throw e;

                }
                return result;
            }
        });
    }
}
